1. Field of the Invention
The present invention relates to magnetic resonance imaging (MRI) technology and, particularly to a method and apparatus for removing artifacts during magnetic resonance imaging.
2. Description of the Prior Art
MRI technology can be used for human vascular imaging, which is called magnetic resonance angiography (MRA). MRA is a magnetic resonance noninvasive vascular examination modality, which has a unique position in diagnosis of vascular diseases, and with the continuous development of the science and technology, and the continuous refinements and developments of the magnetic resonance imaging instrument, MRA is also being developed to image the vascular conditions more finely and accurately.
The time of flight (TOF) method is the most common imaging technology currently used in MRA. The principle of this technique is that: due to the position difference between the flow of blood and static tissue within a time range, it causes the tissue of a saturatedly scanned part to generate a relatively low MR signal, while the unsaturated blood generates a relatively high MR signal.
In the TOF method, maximum intensity projection (MIP) is a relatively common method for displaying an image. The maximum intensity projection is that in every projection direction only the pixels with maximum signal strength are retained. For 3D magnetic resonance TOF technology, typically there are a number of sets of radio frequency pulses at different positions which are used to perform the imaging on a human body, and there is overlapping between these pulses. When using MIP to display the image, artifacts will appear in the overlapped area, and when the artifacts are severe and will have a significant influence on the diagnosis.